1. Field of the Invention
The present invention is a process for preparing phosphonomethylated amino acids, and in particular, for preparing N-phosphonomethylglycine, otherwise known as glyphosate.
2. Related Information
Certain phosphonomethylated amino acids, e.g. glyphosate and its derivatives, are herbicides. Herbicides are useful for controlling or modifying plant growth. Glyphosate and its derivatives are effective in controlling or modifying growth in a wide variety of plant species, including broadleaves, grasses and sedge.
Because glyphosate and its derivatives are so important, new processes for making it and its derivatives faster, cheaper or in greater yields are constantly in demand. A new process for preparing glyphosate and its derivatives has now been discovered.
U.S. Pat. No. 4,439,373 (Nagubandi, Mar. 27, 1984) discloses a process for preparing phosphonomethylated amino acids by reacting a primary amino acid ester or salt with a carbon dioxide group to form a glycine carbamate compound then phosphonomethylating said amino compound to obtain a phosphonomethylated amino compound and acidifying said phosphonomethylated amino compound to expel carbon dioxide and yield a phosphonomethylated amino acid or acid derivative.
British Patent No. 1,413,137 (Beauhaire et al., Nov. 5, 1975) generally discloses using an emulsifiable oil in a process for the cold rolling of light metals. The reference specifically discloses the use of sodium and triethanol amine sulfur amido acetate in this process.
A process for preparing a phosphonomethylated amino acid by first forming an N-sulfonylglycine derivative then phosphonomethylating said derivative then further hydrolyzing the resulting product to obtain the phosphonomethylated amino acid would be advantageous.
It is an object of the present invention to provide a process for preparing phosphonomethylated amino acids.
Other objects and advantages of the present invention are shown throughout the specification.